1. Field Of the Invention
The present invention relates generally to internal combustion engines and, more specifically, to a cold start fuel preheat system for improved atomization of fuel in an internal combustion engine.
2. Description of the Related Art
It is known to provide a fuel-air mixture for an internal combustion engine, which needs good preparation of liquid fuel such as gasoline and air to burn efficiently. This is accomplished by a fuel injection system comprising a carburetor or fuel injector. The ideal fuel-air mixture delivered to the intake manifold should be a homogeneous mixture of minute fuel particles in air to facilitate subsequent vaporization of the liquid fuel. The mixture should have composition or strength to develop maximum economy for each condition of engine operation. When an engine is burning such an ideal fuel-air mixture, maximum combustion of the fuel is achieved while smoke and unburned fuel in the exhaust are held to a minimum.
Cold fuel temperatures are known to result in severe degradation of atomization quality and fuel vaporization rate. These effects result in the need to utilize enrichment strategies to guarantee stable operation of the cold engine. Enrichment strategies require that fuel in excess of that required for normal engine operation be injected to ensure that enough fuel vapor is available in the combustion chamber.
The need for improving the fuel-air mixture in the combustion chamber has been recognized for many years. One attempted solution to this need has been to install electrically heated fuel injectors in the internal combustion engine to preheat and improve atomization of the fuel. However, there is still a need in the art, during cold start, to improve fuel atomization and vaporization, reduce hydrocarbon (HC) emissions, and reduce fuel consumption.